Sterling Silver Marcasite Lavender Natural Quartz Oval Butterfly Pendant Necklace, 18" Sterling silver necklace featuring a butterfly flustered in Marcasite gemstones over a large Oval Lavender Natural Quartz. Sterling silver 18" Singapore chain. Spring ring clasp. Natural Quartz is commonly treated and impregnated with polymers to enhance its color and improve its stability. Marcasite can appear iridescent in the light. The natural properties and composition of mined gemstones define the unique beauty of each piece. The image may show slight differences to the actual stone in color and texture.